Produção de zeólita LTA derivada de cinzas de bagaço de cana-de-açúcar

Abstract

The Brazilian sugar and alcohol sector is of significant importance to the national economy, while Brazil is considered one of the world's largest producers of sugar cane. However, the processing of this biomass in industries causes environmental impacts due to the large amount of waste generated. Therefore, it is essential to develop research that aims to contribute to the appropriate disposal of this waste. Therefore, this work aims to add value to sugarcane bagasse ash through its use for the synthesis of LTA zeolite. The sugarcane residues, as well as the synthetic material, were characterized physicochemically by X-ray fluorescence (XRF), X-ray diffraction (XRD), thermal analysis (TG and DTG) and texture (BET) . After characterizing the silicate precursor material, it was found that the most suitable for the synthesis of LTA zeolite would be heavy ash (CP), as it has: a higher percentage of SiO2 (69.34%), a lower concentration of impurities (5.37 to 6.51%), and greater thermal stability (mass loss of 9.17%). Subsequently, the heavy ash underwent an acid treatment before the synthesis process, in which the analyzes proved to be relevant, promoting the reduction of impurities, greater intensity of silica peaks and an increase in specific surface area. The results of the samples obtained after the synthesis showed the effectiveness of the hydrothermal process, using five proportions of the reaction mixture (ash/Al(OH)3), presenting the following results: Si/Al ratios between 1.56 and 1.78 ; formation of LTA zeolite, together with other SOD zeolite and aluminosilicate phases; mass losses of 5 to 9.5%; specific surface area of 4.638, 4.775 and 4.307 m2/g, with pore volumes of 0.023, 0.026 and 0.028 cm3/g (syntheses 1, 3 and 5). Thus, the ash from the combustion of sugarcane bagasse showed promise for use in the synthesis of zeolites.